export default {
    namespaced: true,
    
    state: () => ({
        // 购物车的数组，用来存储购物车中每个商品的信息对象
        // 每个商品的信息对象，都包含如下 6 个属性：
        // { goods_id, goods_name, goods_price, goods_count, goods_small_logo, goods_state }
        cart: JSON.parse(uni.getStorageSync('cart') || '[]')
    }),
    
    mutations: {
        addToCart(state,goods) {
            const findResult = state.cart.find(x => x.goods_id === goods.goods_id)
            console.log(findResult)
            if(!findResult) {
                state.cart.push(goods)
            } else {
                findResult.goods_count++
            }
            // console.log(state.cart)
            this.commit('m_cart/saveToStorage')
        },
        
        saveToStorage(state) {
            uni.setStorageSync('cart', JSON.stringify(state.cart))
        },
        
        updataGoodsState(state,goods) {
            const findResult = state.cart.find(x => x.goods_id === goods.goods_id)
            
            if(findResult) {
                findResult.goods_state = goods.goods_state
                this.commit('m_cart/saveToStorage')
            }
        },
        
        updataGoodsCount(state, goods) {
            const findResult = state.cart.find(x => x.goods_id === goods.goods_id)
            
            if(findResult) {
                findResult.goods_count = goods.goods_count
                this.commit('m_cart/saveToStorage')
            }
        },
        
        // 根据ID删除商品
        removeGoodsById(state, goods) {
            state.cart = state.cart.filter(x => x.goods_id !== goods.goods_id)
            this.commit('m_cart/saveToStorage')
            
            // const findIndexResult = state.cart.findIndex(x => x.goods_id === goods.goods_id)
            // if(findIndexResult) {
            //     state.cart.splice(findIndexResult, 1)
            //     this.commit('m_cart/saveToStorage')
            // }
        },
        
        // 更新购物车中所有商品的勾选状态
        updateAllGoodsState(state, newState) {
            state.cart.forEach(x => x.goods_state = newState)
            
            this.commit('m_cart/saveToStorage')
        }
    },
    
    getters: {
        // 所有商品的总数量
        total(state,) {
            // let c = 0
            // state.cart.forEach(x => c += x.goods_count)
            // return c
            
            return parseInt(state.cart.reduce((total, item) => total += item.goods_count ,0))
        },
        
        // 已选中商品的总数量
        checkedCount(state) {
            return state.cart.filter(x => x.goods_state).reduce((total,item) => total += item.goods_count,0)
        },
        
        // 已勾选商品的总价
        checkedGoodsAmount(state) {
            return state.cart.filter(x => x.goods_state).reduce((total, item) => total += item.goods_count * item.goods_price, 0).toFixed(2)
        }
    }
}